(CNN) — UK Prime Minister Boris Johnson issued a statement Saturday thanking the National Health Service staff at St. Thomas’ Hospital following his treatment for coronavirus, saying “I can’t thank them enough. I owe them my life,” according to the UK Press Association.

This is the first known statement from the Prime Minister since he entered hospital last Sunday night.

Johnson announced he tested positive for the novel coronavirus on March 27. He said he was experiencing “mild symptoms” and would continue leading the country — while self-isolating in his apartment in Downing Street.

But 10 days later, 10 Downing Street announced the 55-year-old was not getting better and was taken to St. Thomas’ Hospital in London. He was moved to an intensive care unit (ICU) the next day after his condition deteriorated.

Johnson spent three nights in intensive care and received “standard oxygen treatment,” according to his spokesman, but did not require mechanical or invasive ventilation.

He was moved out of the ICU on Thursday night. On Friday, a spokesperson said the Prime Minister was “able to do short walks” in between periods of rest and waved his thanks to staff.

He “is in extremely good spirits,” the spokesperson added.

Half brother criticizes Johnson’s medical treatment

Earlier on Saturday, Boris Johnson’s half brother criticized the medical treatment the Prime Minister received before he was admitted to the hospital.

“From what I gather — and I wasn’t there — no one asked a doctor to mask up and physically examine him the whole time — more than 10 days,” Max Johnson said about the time his brother spent in self-isolation.

In a statement to CNN, Max Johnson said that while he was grateful for the care his brother received from the National Health Service, he wasn’t pleased with the events leading up to his hospitalization.

“He’d tested positive so there was no doubt what he was dealing with. The word ‘shambles’ comes to mind,” Johnson said. “What’s the point of bodyguards when you can’t have a doctor? The Office of Prime Minister needs better protection.”

In response to Max Johnson’s comments, Downing Street described the Prime Minister’s health as a “private matter” adding it would be “inaccurate” to suggest Boris Johnson hadn’t been physically examined by a doctor before entering hospital.

Officials around the Prime Minister have expressed gratitude for all the care he’s had from his National Health Service doctors.

Johnson’s hospitalization shook the nation

The strength with which Covid-19 struck the Prime Minister surprised many in the UK. Johnson is known for his lively persona, so the idea of him being incapacitated shook the nation.

Well-wishes poured in from across the political scene, with even some of Johnson’s old foes expressing their hope he’d recover swiftly.

Meanwhile, those leading the country’s coronavirus response team said Johnson’s hospitalization was a reminder of just how indiscriminate the virus can be and urged Brits to resist the good weather over the Easter weekend and stay at home.

As of Saturday, 9,875 people have died the UK after testing positive for coronavirus, according to a tally by the Department of Health and Social Care. Nearly 79,000 people have tested positive.